Should we thank our well-behaved Sun for our comfy home on Earth?
Some stars behave poorly. They’re unruly and emit powerful stellar flares that can devastate life on any planets within range of those flares. New research into stellar flares on other stars makes our Sun seem downright quiescent.
Red dwarf stars are the most common kind of star in our neighbourhood, and probably in the Milky Way. Because of that, many of the Earth-like and potentially life-supporting exoplanets we’ve detected are in orbit around red dwarfs. The problem is that red dwarfs can exhibit intense flaring behaviour, much more energetic than our relatively placid Sun.
So what does that mean for the potential of those exoplanets to actually support life?
Stars exhibit all sorts of behaviors as they evolve. Small red dwarfs smolder for billions or even trillions of years. Massive stars burn hot and bright but don’t last long. And then of course there are supernovae.
Some other stars go through a period of intense flaring when young, and those young flaring stars have caught the attention of astronomers. A team of researchers are using the Atacama Large Millimeter/sub-millimeter Array (ALMA) to try to understand the youthful flaring. Their new study might have found the cause, and might have helped answer a long-standing problem in astronomy.
Even though the black hole at the center of the Milky Way is a monster, it’s still rather quiet. Called Sagittarius A*, it’s about 4.6 million times more massive than our Sun. Usually, it’s a brooding behemoth. But scientists observing Sgr. A* with the Keck Telescope just watched as its brightness bloomed to over 75 times normal for a few hours.